Background
During an asthma exacerbation, pulmonary function test parameters (PFTs) return to their baseline values within a few weeks. Factors affecting the recovery of PFTs other than the severity of exacerbation are not well known.
Objective
The primary aim of the study was to determine the risk factors for recovery of PFTs > 7 days after a moderate to severe asthma exacerbation in children.
Methods
Children who had moderate to severe asthma exacerbation performed serial prebronchodilator PFTs on days 1, 3, 7 of the exacerbation and then once weekly until their PFTs reached a plateau. All children received systemic corticosteroid for 3 days and inhaled salbutamol as long as they needed.
Results
Fifty‐seven children were recruited. When all PFTs were considered, 42% and 74% of children recovered within 7 and 14 days, respectively. The last recovered PFT parameter was FEF25–75. Allergic rhinitis (AR) (P = 0.016), persistent AR (P = 0.005), and severe asthma exacerbation (P = 0.009) were significantly higher in children whose PFTs recover >7 days; only severe asthma exacerbation was different for recovery >14 days (P = 0.048). Logistic regression analysis revealed that AR and severe asthma exacerbation increase the recovery of PFTs > 7 days by 4.3 (95% CI: 1.29–14.67) and 8.1 (95% CI: 1.51–44.43), respectively.
Conclusions
Recovery of PFTs during a moderate/severe asthma exacerbation may take up to 4 weeks. Apart from severity of the exacerbation, AR is a significant factor affecting the recovery time of PFTs and therefore may impact asthma management. This issue reinforces the combined treatment of AR and asthma.